CN111636480A - A prefabricated integrated pipe gallery and its assembling method - Google Patents

Abstract

The invention discloses a prefabricated and assembled integrated pipe gallery adopting ultra-high toughness cement-based composite material and an assembling method thereof. The comprehensive pipe gallery structure is composed of two bottom prefabricated parts and one top prefabricated part assembled to form an arched section, and the connection position is cast-in-place with ultra-high toughness cement-based composite materials. The prefabricated parts are composed of corrugated steel plates, ultra-high toughness cement-based composite materials, and shear connectors. The ultra-high toughness cement-based composite material on the outside of the corrugated steel plate in the integrated pipe gallery structure proposed by the invention not only significantly improves the bearing performance of the structure, but also plays an anti-corrosion effect of blocking the complex external soil environment. The prefabricated parts are completely transported to the site after being processed in the factory, which is easy for industrial integration and ensures the machining accuracy and quality of the prefabricated parts; the construction site is assembled and a small amount of cast-in-place work is carried out to shorten the construction period and significantly reduce the cost.

Description

A prefabricated integrated pipe gallery and its assembling method

technical field

The invention relates to the technical field of structural engineering, in particular to a prefabricated and assembled integrated pipe gallery using an ultra-high toughness cement-based composite material and an assembly method thereof.

Background technique

Urban underground integrated pipe gallery (referred to as integrated pipe gallery) refers to the public tunnels used for centralized layout of municipal pipelines such as electric power, communication, radio and television, water supply, drainage, heat, gas, etc. in the city underground. Intensive urban infrastructure. The integrated pipe gallery solves the problems of dense overhead line network, repeated road excavation, and frequent pipeline accidents, which is conducive to ensuring the functions of urban infrastructure, beautifying the urban environment, and improving the quality of urban development and comprehensive carrying capacity. With the deepening of my country's urbanization process and the improvement of urban construction standards, based on the advantages of comprehensive pipe corridors, the promotion and support of comprehensive pipe corridors at the national level have been increasing. In recent years, many cities in China have begun to lay comprehensive pipe corridor networks. .

Reinforced concrete integrated pipe gallery is relatively common in practical projects, and the main structure of arched reinforced concrete pipe gallery is usually formed by prefabrication or cast-in-place. Due to the heavy weight of concrete and the tendency to crack on the tensile side under bending loads, it has been gradually replaced by the integrated pipe gallery with steel plates as the main body in recent years. Using steel plate as the main structure of the pipe gallery can significantly reduce the weight of the structure, facilitate construction, shorten the construction period and reduce labor costs. However, due to the complex underground environment where the integrated pipe gallery is located, it is easy to cause corrosion of the steel; in order to prevent the corrosion of the steel, electroplating the steel or laying waterproof materials will increase the structural cost. On the other hand, smaller thickness steel plates are prone to buckling failure, increasing the risk of structural failure.

In recent years, with the continuous improvement of the country's industrialization level, the construction industry is required to gradually implement industrialized and prefabricated construction and construction. The traditional integrated pipe gallery form and construction method of a large amount of cast-in-place concrete cannot meet the current development trend of the construction industry, and it is urgent to propose a comprehensive pipe gallery structure with a higher degree of assembly.

Ultra-high-toughness cementitious composites are new high-performance materials obtained by adding fibers to concrete, and have received extensive and in-depth research in recent years. With a properly proportioned ultra-high toughness cement-based composite material, the fiber content is only about 2% of the total volume of the composite material, and its ultimate tensile strain can reach more than 10% (about 1000 times that of ordinary concrete), and the ultimate tensile strength The strength is up to 20MPa, and it exhibits significant tensile strain hardening characteristics. When the tensile limit is broken, the crack width can be controlled within 100 microns, or even 40 microns. Due to the excellent tensile properties of ultra-high toughness cement-based composites, it can effectively prevent the intrusion of water and chloride ions due to concrete cracks.

SUMMARY OF THE INVENTION

In order to improve the problem that the traditional steel plate integrated pipe gallery is easy to corrode, and improve the construction efficiency and assembly level of the structure, the present invention provides a prefabricated prefabricated integrated pipe gallery using ultra-high toughness cement-based composite materials and an assembly method thereof.

A prefabricated integrated pipe gallery includes a concrete base and a prefabricated part installed on the concrete base, the prefabricated parts include: two bottom prefabricated parts connected with the concrete base, and the two prefabricated parts are connected to the concrete base. a top prefab fitted with a bottom prefab;

A connection layer is formed by casting in-situ ultra-high toughness cement-based composite material at the connection between the bottom preform and the top preform.

In the integrated pipe gallery structure, the two bottom prefabricated parts and one top prefabricated part are assembled to form an arch, and are supported on the concrete base.

The joints between the bottom prefab and the top prefab are connected by tie bolts, and the ultra-high toughness cement-based composite material is cast in-situ at the joint to form a connecting layer.

In the integrated pipe gallery structure, the prefabricated parts include: corrugated steel plates, shear connectors arranged on the corrugated steel plates, and reinforcement layers formed by pouring ultra-high toughness cement-based composite materials on the corrugated steel plates , the processing process of the prefabricated parts is completed in the factory and transported to the construction site for assembly.

The corrugated steel plate adopts a sinusoidal corrugated steel plate, and the sinusoidal wave-like structure on the corrugated steel plate is arranged along the length direction of the comprehensive pipe gallery.

The corrugated steel plate of the bottom prefab extends and leaves a connection port, and the corrugated steel plate of the top prefab extends and leaves a connection port, which is convenient for connection with a tie bolt.

A method for assembling a prefabricated integrated pipe gallery, comprising the following steps:

1) Install the shear connector on the corrugated steel plate first, and then pour the reinforcement layer formed by the ultra-high toughness cement-based composite material on the corrugated steel plate to obtain the bottom prefabricated part and the top prefabricated part respectively;

2) Install the bottom prefabricated part and the top prefabricated part on the concrete base, assemble the two bottom prefabricated parts and one top prefabricated part to form an arch, connect with tie bolts, and then cast in-situ ultra-high toughness cement-based composite materials to form Connect the layers to complete the assembly of the integrated pipe gallery.

The ultra-high toughness cement-based composite material adopted by the present invention includes cement, active mineral admixture, aggregate, fiber and water, wherein the cement and active mineral admixture adopt the following raw materials by weight:

The comprehensive pipe gallery structure proposed by the present invention adopts the method of assembling and forming steel plate-ultra-high toughness cement-based composite material combined prefabricated parts, and has the following advantages:

(1) The ultra-high toughness cement-based composite material used has high compressive bearing capacity, exhibits strain hardening characteristics when in tension, and the ultimate tensile strain can stably reach more than 3%, so it can ensure the synergy between it and the corrugated steel plate Stress; the corrugated steel plate and the ultra-high toughness cement-based composite material form a combined section, and use the synergistic working mechanism and combined effect between the two to produce a "1+1>2" structural bearing performance.

(2) The proposed integrated pipe gallery structure is composed of prefabricated parts. The prefabricated parts are completely processed in the factory and transported to the site, which is easy to industrialize and integrate, and ensures the machining accuracy and quality of the prefabricated parts; Assembly construction, and a small amount of cast-in-place operation of ultra-high toughness cement-based composite materials, high construction efficiency, greatly shortening the construction period and reducing labor costs.

(3) When the ultra-high toughness cement-based composite material is stretched, many fine cracks can be generated, which can effectively block the contact between the internal steel plate and the complex environment of the soil, and play a role in preventing rust of the steel.

(4) The ultra-high toughness cement-based composite material outside the corrugated steel plate in the integrated pipe gallery structure proposed by the present invention not only significantly improves the bearing performance of the structure, but also plays an anti-corrosion effect of blocking the complex external soil environment. The prefabricated parts are completely transported to the site after being processed in the factory, which is easy for industrial integration, and ensures the processing accuracy and quality of the prefabricated parts; the construction site is assembled and a small amount of cast-in-place work is carried out to shorten the construction period and significantly reduce the cost.

Description of drawings

Figure 1 is a front view of a comprehensive pipe gallery;

Figure 2 is a top view of the integrated pipe gallery;

Figure 3 is the A-A sectional view of the integrated pipe gallery structure;

Figure 4-1 is the front view of the prefabricated part of the integrated pipe gallery: the prefabricated part at the bottom;

Figure 4-2 is the front view of the integrated pipe gallery prefab: the top prefab;

Figure 5-1 is a detailed view of the connection point B of the prefabricated parts of the integrated pipe gallery: before the cast-in-place ultra-high toughness cement-based composite material;

Figure 5-2 is a detailed view of the connection point B of the prefabricated parts of the integrated pipe gallery: after the cast-in-place ultra-high toughness cement-based composite material;

Figure 6 is a C-C sectional view of the connection point of the prefabricated part of the integrated pipe gallery.

Detailed ways

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 6 .

As shown in Figure 1, a prefabricated integrated pipe gallery using ultra-high toughness cement-based composite materials includes the following components: prefabricated parts, including two forms: bottom prefabricated part 1-1, top prefabricated part 1-2; Connection layer 2 formed by cast-in-situ cement-based composite material with ultra-high toughness; concrete base 3.

As shown in Figures 1 and 2, the integrated pipe gallery structure is composed of prefabricated parts, a connecting layer 2 formed by cast-in-place ultra-high toughness cement-based composite materials, and a concrete base 3; as shown in Figure 2, the prefabricated parts include a bottom Prefab 1-1 and top prefab 1-2. The prefabricated parts are processed in the factory and transported to the construction site for assembly.

As shown in Figures 1-2, in the integrated pipe gallery structure, two bottom prefabricated parts 1-1 and one top prefabricated part 1-2 are assembled to form an arched section and supported on a concrete base 3.

As shown in Figure 3, Figure 4-1, and Figure 4-2, in the integrated pipe gallery structure, the prefabricated parts are composed of corrugated steel plates 4, reinforcement layers 5 formed by ultra-high toughness cement-based composite materials, and shear connectors 6; The processing of piece 1 is completed in the factory and transported to the construction site for assembly. The corrugated steel plate 4 adopts a sinusoidal corrugated steel plate, and the sinusoidal wave-like structure on the corrugated steel plate 4 is arranged along the length direction of the comprehensive pipe gallery.

As shown in Figure 5-1, Figure 5-2 and Figure 6, in the integrated pipe gallery structure, the bottom prefabricated part 1-1 and the top prefabricated part 1-2 are connected by tie bolts 7. The connection layer 2 is formed by pouring the ultra-high toughness cement-based composite material. The corrugated steel plate 4 of the bottom prefab 1-1 is extended to leave a connection port, and the corrugated steel plate of the top prefab 1-2 is extended to leave a connection port, which is convenient to use the tie bolt 7 for connection.

The ultra-high toughness cement-based composite material used in the present invention comprises cement, active mineral admixtures, aggregates, fibers and water, and the active mineral admixtures include fly ash, silica fume, granulated blast furnace slag, metakaolin , the maximum particle size of the aggregate is not more than 0.5mm, and the fiber adopts one or more combinations of polyvinyl alcohol fiber, polyethylene fiber, and aromatic polyamide fiber. The fiber length is 5mm~25mm, and the diameter is 0.015mm~ 0.055mm, the elastic modulus is 30GPa~150GPa, the tensile strength is 1000MPa~3500MPa, the ultimate elongation is 2%~15%, and the weight ratio of each component of cement and active mineral admixture is:

The performance test of the ultra-high toughness cement-based composite material obtained under the above mixing ratio shows that its uniaxial tensile strength can reach 5.7% (1.3 times that of concrete of the same strength), and the ultimate tensile strain can reach 3.2% (about 3.2% of concrete). 320 times), the corresponding crack width at the ultimate tensile strain is 0.049mm; the flexural strength is 12.8MPa (about 2 times that of concrete), the uniaxial compressive strength is 48MPa, and the compressive strain corresponding to the peak load is 0.55% (about 2 times that of concrete).

In the prefabricated integrated pipe gallery proposed by the present invention, the ultra-high toughness cement-based composite material used not only has the function of anti-cracking and anti-seepage, but also acts as a structural component to improve the bearing performance of the overall structure. The research shows that when the thickness of the sinusoidal corrugated steel plate commonly used in engineering is 2mm, the amplitude is 25mm, and the wavelength is 125mm, the bending stiffness of the plate per unit width around the strong axis is 30.8kN m, and the bending stiffness around the weak axis is 0.14kN·m; when the ultra-high toughness cement-based composite material with a thickness of about 50mm is attached to the outer side, the bending stiffness of the plate in two orthogonal directions can be increased to more than 200kN·m, even if it is around the strong axis. The bending stiffness is increased by 7 times, and the bending stiffness around the weak axis is increased by more than 1000 times. Due to this improvement, the stiffness, strength and stability of the integrated pipe gallery structure under out-of-plane loads can be significantly improved, which greatly improves the structural bearing efficiency and reduces costs.

Claims (7)

1. A prefabricated integrated pipe gallery, comprising a concrete base and a prefabricated part installed on the concrete base, wherein the prefabricated part comprises: two bottom prefabricated parts connected to the concrete base a top preform installed in cooperation with the two bottom preforms; A connection layer is formed by casting in-situ ultra-high toughness cement-based composite material at the connection between the bottom preform and the top preform. 2 . The prefabricated integrated pipe gallery according to claim 1 , wherein the two bottom prefabricated parts and one top prefabricated part are assembled to form an arch, and are supported on the concrete base. 3 . 3. The prefabricated integrated pipe gallery according to claim 1 is characterized in that, the joints between the bottom prefabricated parts and the top prefabricated parts are connected by tie bolts, and cast-in-situ ultra-high toughness cement base is used at the joints. The composite material forms the tie layer. 4. The prefabricated integrated pipe gallery according to claim 1, wherein the prefabricated parts comprise: corrugated steel plates, shear connectors arranged on the corrugated steel plates, and ultra-high toughness cement-based composites The material is cast on the corrugated steel sheet to form a reinforcement layer. 5 . The prefabricated integrated pipe gallery according to claim 1 , wherein the corrugated steel plate is a sinusoidal corrugated steel plate. 6 . 6 . The prefabricated integrated pipe gallery according to claim 1 , wherein the corrugated steel plate of the bottom prefab extends and leaves a connection port, and the corrugated steel plate of the top prefab extends and leaves a connection port. 7 . 7. A construction method for a prefabricated integrated pipe gallery, characterized in that, comprising the following steps: 1) Install the shear connector on the corrugated steel plate first, and then pour the reinforcement layer formed by the ultra-high toughness cement-based composite material on the corrugated steel plate to obtain the bottom prefabricated part and the top prefabricated part respectively; 2) Install the bottom prefabricated part and the top prefabricated part on the concrete base, assemble the two bottom prefabricated parts and one top prefabricated part to form an arch, connect with tie bolts, and then cast in-situ ultra-high toughness cement-based composite materials to form Connect the layers to complete the assembly of the integrated pipe gallery.

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